Diminishing Parental Care In Some Late Nesting Martins

[Steve Kroenke]

Diminishing Parental Care In Some Late Nesting Martins

Purple martins are a highly colonial and migratory species. They spend a good portion of their lives on the go, as they travel with other martins between their wintering grounds in South America and their nesting sites throughout the United States and Canada. So, the instinctive drive to migrate with the flock is deeply engrained in a martin’s genes and behavior. This drive is highly prevalent toward the end of the nesting season when nearly all martins have finished breeding and are forming pre-migratory flocks in preparation for the flight south. The urge to assemble and migrate south seems to dominate the purple martin species after the young have fledged and are independent. Martins have a long journey ahead of them and they must also finish molting all their feathers while on their wintering grounds. Migration instinct is extraordinarily strong in purple martins.

Competition Between Instinctive Drives In Late Nesting Purple Martins

This highly developed migratory drive will sometimes compete with a martin’s instinct to stay with its young, particularly when nearly all martins in the area have finished breeding and are heading south. Late nesting martins may be torn between the urge to migrate with the flock and the urge to continue staying behind and feeding their babies. When there is only one pair of nesting martins left at a colony, the conflict between the drives may be particularly strong. These are often, but not always, sub adult martins (SY) that have colonized a new site or are nesting at an older, established colony. When martins initiate such late nesting behavior, any young produced may be nest bound until late July into September depending on the geographical location of the colony. By this time, many martins are forming pre-migratory roosts or heading south. This may exert migratory pressures on these late nesting parent martins as they try to feed their young while suppressing their desire to fly with the flock and head south.

Late Nesting Martin Feeding Behavior/Parental Care

Most martins that are nesting during the “normal” breeding period for their area begin feeding their young at dawn, often while there are dim lighting conditions. They continue to feed their babies throughout the day, with occasional “slow down periods”, and persist until the evening. I have observed martins start feeding their babies just after 6:00 am and stop between 8:30 and 9:00 pm.

For very late nesting pairs, particularly those where all the other martins have finished breeding in the colony, you may observe significant variations from the “norm” relative to feeding young. Late nesting martins may vary considerably in their frequency and daily time frames of feedings to their young. If these late nesters are not roosting with their young, then the parents may arrive later in the mornings to begin feedings. I have observed some of these parents arrive at 8:00 am or later to begin feeding their young though most returned earlier. During the day, their feedings may be sporadic at times with the parents leaving the area during the late afternoon. Sometimes both parents will be gone when there are still several hours of daylight left to feed the young. I have observed some of these late nesting adults leave the area by 6:00 pm or even earlier. Both the beginning and ending feeding times for late nesting martins are greatly impacted by the age of the young and roosting behavior of the parents. If one or both of the parents are roosting with their babies, then you may see a more “normal” feeding schedule, starting early and ending before dark. However, even these roosting parents may start feeding their young later than normal.

When parent martins arrive late at the nest in the mornings and leave early in the afternoons, this behavior may relate to the distance they must fly to reach the closest pre-migratory roost site. If neither of the parents is roosting with the young, the adults are probably spending the night at the nearest pre-migratory roost. If it is late in the season and most martins are gone from the area, then there may be no nearby roosts, so the parent martins may be flying many miles to reach the closest one. This could result in several hours of flight time for the parent martins in the mornings to arrive at the nest and in the afternoons to reach the communal roost.

Also, late nesting martins must face much higher daytime temperatures and this factor can impact the number of feedings to the young. During extremely high temperatures in the upper 90s for example, insects, such as dragonflies, may not be flying in large numbers, thereby reducing the prey base for the parent martins. The young martins may become heat stressed and not be as responsive to the food stimulus.

And, just prior to fledging their young, parent martins will start reducing the daily feedings to prepare their babies’ transition from nestlings to fledglings. Hungry young are more prone to fledging than well fed ones, particularly when the parents tempt them with a dragonfly. So, it is normal to see fewer feedings during the last week prior to the young making their maiden flight.

There May Be Significant Differences In Feeding Behavior Between Male and Female Martins

From my observations of these very late nesting pairs, you may see significant gender differences between male and female martins in feeding their young. The female martin is clearly more attentive to the young and spends more time with her babies than her mate. This is largely a function of the specific gender roles in purple martin family life. The mother martin broods her young during their early lives and she usually roosts at night with the babies for much longer than the male. Some males may quit roosting with their families after the young are older and nearing fledging. For late nesting pairs, the males may quit roosting with their families soon after the young have hatched.

Late nesting male martins may show reduced parental care to their young by feeding them fewer times than normal and then leaving earlier in the day. This may become more pronounced after the young are about two weeks old and it is later in the breeding season. These males may arrive at the nest site later in the mornings and feed the young a few times. Then they may disappear for long periods and show up again later with an occasional food item. Generally, their feedings to the young may be lower than the females. Other males may function mainly as guardians to the nest and chase away other males, particularly SYs that try to enter the cavity. These males may stay around the nest site in the mornings and bring in an occasional dragonfly. Then they gradually disappear in the afternoons and will not return until the next day. Some males may eventually abandon their families after the young are older or just after fledging. I had several cases where the males finally just quit coming around and the female went solo to finish raising the young.

Female martins are extremely attentive to their young and closely bonded to them. Nurturing the young is a key gender role of the female martin. Females usually feed late hatching young reliably and provide good parental care. I never had a case where a female abandoned her late hatching young though some of these females may not feed their young as often as normally. Also, these females roosted with their babies almost up until fledging and some through that time. However, I did observe several situations where non-roosting females with older young would arrive late in the morning to start feeding their babies and then departed relatively early in the afternoon. In these cases, the females may have been flying many miles to reach a communal pre-migratory roost. Again, the females are usually much more bonded to their young than the males and provide better parental care in late nesting situations.

Differences Between Late Nesting ASY Pairs And SYs

Generally speaking late nesting ASY pairs, both male and female, are more attentive to their young and provide more reliable parental care. These martins have most likely successfully raised young in the past and this experience no doubt helps them. Late nesting ASY males are probably more prone to feed their babies at higher rates than the SYs. The SYs, particularly the males, are raising young for the first time and embarking on this most important and potentially stressful adventure late in nesting season does create a challenging situation. However, I have seen both late nesting ASY and SY males significantly reduce their feedings to their nest bound young and even abandon their family prior to the babies fledging.

Late Nesting Fledglings

When late nesting youngsters fledge, I have observed cases where the parents or female parent brought their young back to roost in their natal nest for several nights and in other situations where they all disappeared. However, I did have several cases where the females brought their young back for longer than a week. It is possible that these youngsters may have greater difficulties in surviving to independence since the parents are under pressure to migrate with the flock. This may result in reduced parental care after fledging. However, martin youngsters grow up fast and learn to hunt flying insects quickly. So, that is a good behavioral adaptation to possibly help martins overcome problems with fledging later in the nesting season.

Summary

Purple martins are highly migratory birds and are nomadic for a good portion of their lives. This powerfully developed drive to “go with the flock” at the end of the nesting season may sometimes conflict with an equally strong drive to feed late hatching young. This “battle of the instincts” may result in some parent martins, particularly the males, reducing their feedings to nest bound young or abandoning their families. Most females tend to be more closely bonded to their young and often maintain a good level of parental care in late nesting situations. These females continue to feed their babies reliably, roost with them until fledging, and may bring them back to sleep in the evenings for several nights or longer.

Steve Kroenke

[Steve Kroenke]

Right now, I will have a few pairs of ASY martins that are apparently raising second broods have nest bound young until the end of July or even first of August. This is extremely late for northwest Louisiana and by then nearly all martins will be finished nesting and assembling at premigratory roosts or be heading south. Currently, both male and female of each pair are feeding their babies reliably. However, as it gets later in the season, the males in particular may be begin to show diminishing parental care to their young.

I am re-activating this older posting that deals with subject of diminishing parental care for some late nesting martins. It is important to understand that in every case I have observed the female martin was the primary caretaker of the young while most males reduced their parental involvement. Some males apparently abandoned their families and females raised the young by themselves.

Other folks may have some late nesting martins this season and these landlords may see some diminishing parental care, particularly from the males.

Steve

[CraigMo.]

Thanks Steve, I have this going on right now. I have a new pair and 5 new eggs laid sometime between 7/3 and 7/7.

[Steve Kroenke]

Hey Craig,

I hope your martin pair provides reliable parental care all the way till fledging. Please observe the general feeding rate of both male and female martins as the season progresses and see if you notice a difference.

Oh, I have one ASY pair that have a second clutch of eggs! The is one of my 6 ASY pairs that I believe are going for a second nesting after finishing their first one; the other 5 have newly hatched young. I am not sure if they are going to hatch, but if they do they should be hatching in the next few days. The female reliably incubates the eggs, but her mate hardly comes around. He will sometimes show up in the mornings and visit with his mate. The big test for him will be when the eggs hatch if they do. Will he start feeding his babies and keep it up?

Steve

[Guest]

Steve: The later nesting birds seem to really slow down the feeding so much so that you wonder if the parents are feeding enough. The parents on these late nesters seem at times to care less and only show up a few times an hour or even less and fly slowly in to feed. They do not seem to
have a sense of urgency. However they are usually sucessfull. It has always fascinated me that some martins feed there young like there is no tommorrow and others feed much much less but they are seem to fledge. There must be a very significant difference in the amount of food
it takes to fledge a martin
Thanks, Joe

[Steve Kroenke]

Hey Joe,

What I have noticed over the years is that most martins during the "normal breeding time" feed their young fairly consistently and I don't see male martins "slacking off". Of course, I do see some variation in amount of feeding.

It is mainly the extremely late nesters where I see the greatest impact of "diminishing parental care", particularly for the males. However, like you say, most are eventually successful as long as the female is there, at least that is what I have observed.

Steve

[Steve Kroenke]

This season I will have a few late nesting pairs of SY martins. These martins will be feeding young into mid-July. Over the years I have observed the feeding and parental care behavior of late nesting pairs of martins. Some of the males greatly slack off in feeding their babies and others abandon their families. I have never seen a female abandon her young and the females stayed with their babies until they fledged. Females are usually more attentive to the young than males.

I am re-activating this older article of mine dealing with the subject of diminishing care of young by late nesting pairs of martins. Other folks may have observed similar behavior with their late nesters, too.

Steve

[Steve Kroenke]

Some martin pairs initiate their breeding cycle later than normal and will have babies when most of the other members of a colony have finished nesting. This can result in situations where the parents are under pressure to migrate while still trying to feed nest bound young. I have seen this happen nearly every year in my various martin colonies and in all cases the female martins stayed with their young and usually fledged them. However, many of the males greatly reduced the level of parental care and some even appeared to abandon their families. I am re-activating this older article dealing with the subject of diminishing parental care in some late nesting martins. I am sure other landlords have witnessed similar situations.

Steve

[Craig Dyer]

Hi Steve,

Thanks for sharing your observations and insight. All the young at my site this season have fledged, with one exception. An ASY pair laid a clutch of seven eggs back in early May. None of the eggs hatched. I thought that was the end of the season for this pair. Then, to my surprise, four new eggs appeared. Hatching began on July 4th. If the young survive, it will be late July or early August before they fledge. This will be a new experience for me. I have never had a pair nest this late in the season.

[Steve Kroenke]

Hey Craig,

Thank you for providing information about your late nesting pair of martins! Late nesting martins sometimes have a more difficult time raising their young because of issues with migration instinct, food supply and hot weather. It will be interesting for you to watch both the male and female martin as they take care of their very late brood for your area.

I currently have only three pairs of martins left with nest bound young and all are SY pairs. Our weather is still HOT and dry though we did have a nice rain shower a few days ago. One pair is doing a fairly good job of feeding their young and this is the pair with the smallest babies. If they survive, they should fledge around the third week of July. The other two pairs have older young and are doing a much poorer job of regularly feeding their babies with mainly the female providing some insects. If these babies survive, they should fledge in about a week. One of the females of these older babies does still roost with her young so she will start providing some food early in the morning.

I hope you will keep us posted on the status of your late nesting pair. Good luck.

Steve

[Ron Prichard]

Steve: Enjoyed reading your article ref to parental care during the late season. Had an interesting adult male case this year. I found a dead female adult in the nest with 5 young. I thought, well these young ones are goners as the adult male would probably abandon the young in the nest. Wrong! He kept feeding the young ones by himself. His nest was on the back side of our T-14 but I observed him for days coming in with dragon flys. Unfortunately, he could not keep up. Three young ended up fledging this nest but two died. Not sure if he just picked three of the strongest to feed or the two who died just did not get enought food. Anyway, I had a great deal of admiration for this adult male and his dedication to his nestlings.

Yesterday, it was 108 at 4pm yesterday. More of the same today. We have many jumping the nest. No adult feeding at all from about 12 noon until late pm hours. I fear we will lose what we have left to the heat even though we are trying to mist down the houses about every hour in the afternoon.

Anyway, thanks for the read.

Ron Prichard
Piedmont, OK

[Steve Kroenke]

Hey Ron,

Thanks for sharing your observation of the dedicated male martin that took care of his nestlings. It is most difficult for a single male to raise five babies and most probably can't do it. A single female would probably have a difficult time, but she may be able to better do it.

During periods of extreme heat, many parent martins reduce their feedings considerably as flying insects are probably not as active and the young martins may not be as receptive to food. When the young martins are rarely fed, they not only starve but may become dehydrated as nestlings receive most of their moisture from their food.

I now have only two SY pairs of martins left. One pair's babies are ready to fledge and the other pair's young have about a week to go. Both males are here and actively participating in feeding the young. Feeding trips are reduced in the afternoons when the heat really hits hard. However, our heat has not been as bad as yours. We have temps in the upper 90s and approaching 100 degrees. These last two pairs' babies have survived so far.

Steve